Dishwasher



April 15, 1952 G. B. FOX ETAL DISHWASHER Filed Feb. 21, 1947 7/ 93 INVENTORS 84 2 83 I04 fgqwwl 7/1. M (i/ AT TORNEYS April 15, 1952 5 X ETAL 2,592,884

DISHWASHER Filed Feb. 21, 1947 2 SIlEETS-SHEET 2 FIG.3

//2 //5 H6 I20 /23 I22 I25 IN VEN TOR-5 flu /gdd BY vqS-LM vfwzilaw ATTORNEYS Patented Apr. 15, 1952 UNITED STATES PATENT OFFICE DISHWASHER Gerald B. Fox and John M. Sherman, Troy, Ohio,

assignors to The Hobart Manufacturing Company, Troy, Ohio, a corporation of Ohio Application February 21, 1947, Serial No. 730,066

Claims. (0]. 29984) This invention relates to washing machines, and more particularly to a device adapted to introduce disinfectant into a dish washing machine to provide sanitized dishes.

It is a primary function of a dish Washing machine to provide for the washing and rinsing of dishes, silverware, and the like and to remove food particles therefrom, and accordingly it is highly desirable to provide for the delivery of the washed articles in a sanitary and healthhazard-free condition. The washing of dishes and food utensils in a manner to assure a maximum of sanitation, in the sense of minimizing bacteria populations, has received considerable attention over a period of time, and in, many cases special precautions have been taken to assure proper sanitation. Since all dishes are potentially contaminated with undesirable bacteria that must be destroyed if the dishes are to be rendered health-harzard-free, the need of good sanitation is well recognized and particularly in institutions, such as hospitals and the like, care is usually exercised to provide rinses of sufliciently high temperature to assure a complete kill of all disease producing bacteria.

attention from the operator, which provides a" quick acting fluid injecting means having rela- The need of good sanitation in commercial establishments, such as restaurants, bars, soda fountains and the like, is also well recognized by public health officials, but is frequently not as well recognized by the trade. Furthermore, in most cases it has been either impractical or uneconomical to provide rinse water of sufficiently high temperature to destroy objectionable bacteria. The customary supply of rinse water usually found available in this type of installation varies from about 120 F. to about 140 R, which is below that assuring the destruction of bacteria and the obtaining of proper sanitation in such instances is therefore often unsatisfactory.

Accordingly one of the principal objects of this invention is to provide dish washing equipment which will assure the washing of dishes and the like in a manner which will not only free them from adhering food particles or the like, but which will also assure that the dishes are rinsed with a fluid disinfectant before being removed from the washer and therefore will be in a highly sanitary condition and substantially free from bacteria even with the use of lower temperature wash and rinse fluids.

It is another of the objects of the present invention to provide a small, economically manufactured and ruggedly constructed disinfectant injector for a dish washing machine that is easily installed and requires a minimum of service and tively few moving parts, and which is automatic in operation to discharge a relatively small measured quantity of disinfectant fluid at a substantially proportionate rate of flow directly into the rinse supply line connected with. the rinse arms of the machine, so as to insure the proper and efficient use of the disinfectant with every rinse operation.

It is also an object to provide a disinfectant injecting means for a dish washing machine which is designed to operate quietly and rapidly, and to function so effectively in accurately controlling the introduction of a predetermined and relatively small quantity of disinfectant intd' a relatively large quantity of rinse fluid, that even with the operating temperature of the rinse fluid reduced to the order of about F. to F., the bacteria count is drastically cut down and brought within acceptable public health regulations.

Another object resides in the provision of a compact and inexpensive disinfectant proportioner and injector for a dish washing machine wherein a suction action within the rinse supply line is utilized to provide an automatic withdrawal of a measured charge of disinfectant fluid from a supply thereof, and which also makes use of the suction action within the rinse supply line to inject the measured charge of disinfecting fluid back into the same line at a predetermined rate of flow and to thoroughly and substantially uniformly admix it with a considerably larger volume of rinse fluid throughout the entire or substantially the entire time of the rinse cycle of operation.

An additional object is to provide for a dish washing machine an accurately operating disinfectant injecting means which utilizes a venturi in connection with a capillary tube of predetermined diameter and length to provide a proportionate injection of a relatively minute quantity of disinfectant which is distributed through the rinse supply during a rinse cycle of the machine,- andwhich does not require any moving parts to effect the operation thereof and thus is relatively simple in construction, easily installed without the necessity for using skilled labor or special tools, and economical in use and in upkeep.

A further object is to provide for a dish washing machine a disinfectant fluid injecting mechanism connected to operate on a pressure differential produced within an intermediate portion of the supplyline to inject a measured quantity of the disinfectant into the rinse Supply-line at a regulated rate of flow such that a predetermined proportion is maintained between the disinfectant and the rinse fluid, and which is so constructed that a small [portion of the fluid from the supply line can be diverted to flow through the connections between the supply of disinfectant and the rinse supply line to provide for removing sediment or coagulated particles should any collect within the discharge mechanism.

It is also an object to provide a disinfectant injecting mechanism of the character described having a, simple and easily constructed means for connecting the capillary discharge tube thereof to the injecting mechanism and to the disinfectant supply container which also provides a fluid tight seal therebetween, and which can be quickly connected, or disconnected when the supply of disinfectant is to be renewed, without requiring the use of tools or skilled labor.

Another of the objects also resides in the provision of a screen assembly for a disinfectant injector of the character described which is economically manufactured, easily installed, or removed for cleaning, without requiring skilled labor or the use of tools, and which is efflcient in operation to prevent the clogging of the discharge tube leadin from the disinfectant supply container.

Other objects and advantages of this invention will be apparent from the following description, the appended claims, and the accompanying drawings in which:

Fig. 1 is a perspective view, partly broken away and in section, showing the interior of a dish washing machine provided with a disinfectant injecting device constructed in accordance with the present invention;

Fig. 2 is a vertical sectional view through the Venturi tube and ball check valve chamber of the injecting device;

Fig. 3 is a broken front elevational view, partly in section, showing the connector used between the capillary tube and the outlet tube at the top of the disinfectant supply container;

Fig. 4 is a View similar to Fig. 3 illustrating the screen assembly used in the disinfectant supply container; and

Fig. 5 is a schematic diagram showing a preferred arrangement of piping and valves for connecting the rinse arm and the rinse supply line of a dish washing machine with the disinfectant supply container and injector mechanism.

Referring to the drawings which illustrate a preferred embodiment of the invention, and to Fig. l in particulanthere is shown by way of illustrative example a machine for washing dishes or utensils and the like which is generally indicated by the reference numeral 26. A supporting track 2! is provided therein to position a utensil or dish rack (not shown) which is adapted to carry the glasses or dishes to be washed. A semicylindrical cover 22 adapted to enclose the machine is suitably mounted for movement to an open position, providing for the ready insertion and removal of a rack of dishes or utensils, and to a closed position (Fig. 1) when the machine is to be operated. The machine is further provided with a tank or sump 23 communicating I with a centrifugal pump 24 driven by a motor 25 and adapted to circulate a wash fluid contained within the tank upwardly through a system of pipes, generally indicated at 26 in Fig. 5, and into a wash distributor or arm 2? shown as located below the rack carrying the dishes or utensils to be washed, and by means of which the wash fluid is forcibly expelled and recirculated to effect a washing and cleansing of the utensils.

To effectively rinse the utensils after they are washed as described, rinse arms or nozzles 28 are located, preferably above and below the rack carrying the utensils, so that a fresh and clear supply of rinse fluid may be sprayed over the utensils as desired. A pipe 30 connecting the rinse arms 28 in a continuous circuit with the main rinse supply pipe 31 is provided so that the rinse fluid can be introduced from an outside source, such as a public water supply system for example, and can also be heated from an outside source to a desired temperature. Where the wash and rinse operations are kept separate and independent functions of the machine, the wash fluid is recirculated and reused while the rinse fluid is always fresh. However, it is to be understood that the construction of the machine is such that the rinse fluid drains from the dishes and utensils down into the tank holding the wash fluid to replenish such supply of wash fluid, an overflow pipe being provided therein to prevent overflowin of the tank.

To facilitate rapid and easy operation, a valve 32 of the quick opening and closing type has been provided having a connection into the fitting 33 of the rinse line. This valve is handoperated by means of a mechanical linkage which has a shaft 34 connecting with the handle 35. There is also a connection 36, Fig. 5, from the lower end of shaft 34 to the switch 31 in the line controlling the energization of the motor 25 driving the pump 24. Handle 35 when turned from neutral to one position thus provides for starting and stopping the flow of wash fluid into the arm 21, and when turned in the other direction from neutral provides for starting and stopping the flow of rinse fluid into the arms 28, these operations being mutually exclusive.

It has been found desirable for the reasons previously stated to introduce a relatively small quantity of disinfectant into the rinse fluid so that a condition toxic to bacteria will be established under the operating conditions described such that the bacterial content upon the dishes and utensils will be materially reduced. To accomplish this with relatively low temperature rinse fluid, a small quantity of disinfectant is thoroughly admixed with the rinse fluid during each rinse operation. Where, for example, there is a 10 second rinse operation, there may be used approximately 5 to 10 milliliters of about 10% solution of adisinfectant of the type commercially known as quaternary ammonium salt compounds. In this group are classified such compounds described as alkyl dimethyl benzyl ammonium chloride, diisobutyl phenoxyethoxy ethyl dimethyl benzyl ammonium chloride, cetyl pyridinium chloride, oleyl dimethyl ammonium bromide and like compounds. These compounds are known by such trade names as Roccal, B. T. C., Hyamine, Cepryn, Quart-o1, etc. It is also understood that other types of disinfectants, such as hypochlorites, chloramines, phenol derivatives, heavy metals, etc., varying in amounts and concentrations and which are effective bactericides under conditions of operation encountered may also be used.

In operation it is preferred to introduce the disinfectant in the rinse supply line of the dish washing machine by means of an injector mechanism operating on the principle of a Venturl tube. It has been found that where, for example, the Venturi tube is designed to produce an increase in the velocity of the fluid flowin in the rinse supply line at the Venturi throat in the ratio of about 12 to 1 there will be a reduction in pressure producing sufiicient suction to operate the injector mechanism as described.

The injector mechanism, generally indicated by the numeral M, for introducing the disinfectant into the rinse supply line comprises a Venturi tube 42 and a ball check valve body 43, the outer surfaces of which may be in the form of hexagons as shown in Fig. 1.

Tube 42 is provided with a short central bore at each end of sufiicient diameter to receive the nipples 45 and 46 which are adapted to seat against shoulders therein, and are held in place as by brazing at the points 49. This tube is then connected into the rinse supply line 3| by means of unions 53, 54 in the usual manner. In operation it is preferred that the tube 42 be installed in the rinse supply line on the up-stream side of valve 32 as illustrated in Figs. 1 and 5, but it can be connected on the down-stream side thereof by rearranging the piping to provide for that purpose if such location is desired. With the latter arrangement, however, fluid under line pressure cannot be diverted through the valve body 43 to effect a cleaning action.

As most clearly seen in Fig. 2, the interior of tube 42 is drilled to form a tapered bore 56 which extends from the inner end of nipple 46 toward the interior of tube 42 to provide a passage, the internal surface of which is in the form of a truncated cone. Bore 56 is tapered as shown to form an included or total angle of about 6 degrees. Similarly formed in tube 42, a second tapered bore 51 extends from the inner end of nipple 45 toward the interior of tube 42 to provide a passage, the internal surface of which is also in the form of a truncated cone. Bore 51, however, is tapered to form an included or total angle of about 21 degrees.

The passages formed by the bores 56 and 51 in turn converge at their inner ends to form a short horizontal passage or throat 60 which is preferably of the order of about five-sixteenths of an inch in length where, for example, the passages or bores 56 and 51 are of the order of about five and one half inches and two inches in length respectively. Tube 42 is also provided with a vertically stepped bore 62 which converges at its upper end into a relatively small passage 63 which in turn communicates with the throat 66. The bore 62 is internally threaded to receive one end of a hollow nipple 65 which is externally threaded at each end so as to be threadedly received within the bore 62 at one end and at the other end within a vertically stepped bore 66 in the top side of the ball check valve body 43. The lower end of bore 66 extends into the interior of body 43, and the nipple 65 thus provides means for connecting the tube 42 with the body 43 and in addition places them in communication with each other.

Referring to Figs. 1 and2, the ball check valve body 43 comprisesin general a relatively short tube the outer surface of which may be in the form of a hexagon similar to tube 42. This tube is drilled to provide at one end a horizontally stepped bore 10 extending centrally through the tube to form a passage communicating with the vertical bore 66, and with a second vertical bore II also provided therein. It is to be noted with respect to the vertical bore II that the upper end thereof is closed by means of a plug 72 inserted therein to close off the passage and prevent fluid from leaking therefrom. Additionally there are also two horizontally stepped bores 13, 14 provided in the other end of chamber 43, of which bore 13 communicates at its inner end with bore II while bore I4 communicates in turn with both bores 66 and H at their lower ends.

A cartridge member I5 threaded into the bore I0 is externally threaded at the outer end thereof to receivea nut 16 provided to adjustably position the cartridge within the bore so .that the inner end thereof is in proper alignment with the lower end of bore 66. The outer end of this cartridge is also provided with a slot 11 to facilitate properly adjusting the cartridge within the bore In. To prevent leakage from occurring along the exterior surface of the cartridge, a sealing ring of neoprene, or like material, is provided which seats in a groove formed on the exterior surface of the cartridge. At the inner end, the cartridge I5 is drilled to provide a short horizontal bore or passage BI adapted to communicate with the bore 66, bore 8| being of suflicient diameter to receive a coiled spring 84 therein. The inner end of the passage 8|, Fig. 2, is enlarged to provide a cup shaped seat 82 for the ball 83 which serves as a check valve with respect to the bores or passages 66 and I6. Seated within the bore I6, and adjacent ball 83, is an annular collar 85 of stainless steel which also serves as a seat for the ball 83 to close the extreme inner end of the passage formed by th bore III.

A needle valve, generally indicated by the numeral 90, externally threaded and rotatably positioned Within the horizontal bore 14 provides means for adjustably opening and closing the relatively small diameter inner end of the bore passage 14 leading to the lower end of bore 66. The outer end of this valve is free of threads and adapted to project from within the bore 14, and to prevent leakage from occurring between the valve and the bore a sealing ring 92 of neoprene, or like material, is provided which seats in a groove formed in the exterior surface of the valve. The outer end of valve is also provided with a slot 94 to facilitate rotating the valve when it is desired to open or close the inner end of the bore 14.

A capillary tube I60, preferably formed of stainless steel, is connected with valve body 43 by a removable stud IIlI threaded into the bore passage 13. Through this stud extends a cen tral bore of sufllcient diameterto receive tube IllIl. This stud is also provided with a head I02. Positioned within the bore I3, and adjacent the inner end of the stud IOI, is a collar I03 adapted to fit around the exterior of tube I00 so as to abut against a stopper I04, also seated within the bore 13, through which the inner end of tube I66 is i nserted as shown in Fig. 2. This stopper is constructed of neoprene or like material adapted to be deformed when the stud I6 I- is rotated to force the collar I63 into contact therewith and thus provides a sealing means pressing tightly against tube I06 and outwardly against passage I3 to prevent leakage of fluid from within the bore I3.

At its lower end the tube I00 is connected to the upper end of a relatively large diameter cop per tube III] leading from the disinfectant supply container III by a vertically positioned connector generally indicated by the reference nu:

meral H2. This connector has an outer casing H3, Fig. 3, drilled to provide a central bore threaded at its upper end to receive a threaded stud II4. A central bore also extends through this stud which is of suflicient diameter for the lower end of tube I to be inserted therein. An annular collar H similarly bored for insertion around the lower end of tube I00, and a rubber stopper H6, are also provided within the central bore of easing I I3 adjacent the lower end of stud H4. The stopper H6 is constructed preferably of neoprene or other suitable material effective to be deformed when the stud H4 is rotated to force the collar H5 into contact therewith, and thus provides a sealing means to prevent leakage of fluid from occurring either along the exterior surface of tube I00 or along the interior of easing II3.

Casing II3 of the connector I I2 is drilled at its lower end to provide a stepped bore communicating with the central bore at the upper end thereof. Tube I I0, which is of substantially larger diameter than that of tube I 00, is inserted within the lower end of easing I I3 until it seats against the shoulder I provided by the stepped bore, and is held in position by means of a sleeve I22 and a neoprene stopper I23 also positioned within the bore. A cap I25 threadedly received on the lower end of casing H3 completes the connector II2 assembly and provides means for forcing the sleeve I22 into contact with the stopper I23 to deform it both inwardly and outwardly and seal the lower end of easing H3 to prevent leakage therefrom.

The copper tube I I 0 is in turn positioned within the disinfectant supply container I I I by being inserted through an aperture provided in the disk I which forms a removable fitting over the threads on theneck of the container. This cover I30 is constructed preferably of copper, or similar material, and is also provided with an aperture through which a hollow copper tube I33 is inserted, the tube I I0 and the tube I33 being secured therein as by brazing. Tube I33 is open at its upper end to the atmosphere and thus provides for the fluid within container III also being under atmospheric pressure. With this construction it will be readily apparent that when it is desired to substitute a new container, to replenish the supply of disinfectant, it is necessary only to remove the disk I30 from the neck of the exhausted container, lift out the tube H0. reinsert it in the new container and replace the disk I30 thereon. There is thus provided a quick and easily operated means which does not require any special tools or skilled labor for removing an empty container and replacing it with a full one.

At its lower end, within the container III, tube H0 is connected with a strainer assembly generally indicated by the numeral I40, Fig. 4, provided to prevent particles of foreign matter from flowing into the tube. This strainer has a lower cap I4I which is provided with a shank portion I42 having a central bore I43 therein of sufiicient diameter to receive the lower end of tube H0. Cross bores I45 and I46 of relatively small diameter are also provided at right angles to the central bore through the shank I42 of cap I4I as most clearly seen in Fig. 4. Bore I46 is adapted to register with a similar bore provided in the end of copper tube I I0, substantially above the lower end thereof, so that when the tube III] is received within the shank I42 and a pin I4! is inserted through bore I46, these bores will be in register and the cap I4I will be held in place on the end of the tube and the open lower end of the tube H0 will be held above the bottom of central bore I43. The bore I45 can communicate then with the interior of tube H0 through its open end and through the outer surface of the cap, thus placing the interior of the container III in communication therewith and providing a passage through which the disinfectant flows into the interior of the tube. It is to be noted that bore I45 is drilled through shank I42 so close to the bottom of the central bore I43 therein that it can not be made to register with the bore provided through the end of tube H0, even when this tube is seated on the bottom of bore I43, and thus in assembly, tube H0 must be lifted away from the bottom of bore I43 sufficiently to allow assembly of pin I41 through bore I46, thus assuringthat bore I45 will remain open for inflow of fluid.

Slidably mounted upon the tube IIO above the cap MI is a second cap I50 which is provided on its underside with an annular groove I5I of suificient width and depth to receive the upper edge of preferably a LO-mesh wire screen I52. The lower end of this screen is adapted to fit into an annular groove I53 similarly provided on the upper side of the cap I4I. Thus when it is desired to remove the screen I52 for inspection or cleaning, the cap I50 is raised on the tube H0 which frees the screen from groove I5I and permits it to be lifted from its supporting position in the slot I53 on the cap I4I.

In assemblying the injector mechanism 4I, it is preferable to use in the rinse supply line,-Fig. 1, a line strainer I connected at one side to a main water supply line and at the other side to a T-fitting I6I having a removable plug therein to provide for the connecting of a gauge to measure upstream pressure when desired. A pressure reducer I62 is also provided to reduce the line pressure to a maximum pressure of the order of about 30 pounds per square inch at the entrance to the Venturi tube 42, to thus establish a substantially uniform pressure for delivery through the Venturi tube. The pressure reducer.

I62 is in turn connected by means of the union 53 to the injector mechanism 4|. At the other end the injector mechanism is connected by means of the union 54 and a short pipe to the T- fitting I63 which also has a removable plug therein to provide for connecting a gauge when it is desired to measure the down-stream line pressure. This portion of the piping is completed with an elbow connection leading from the T- fitting I63 into the rinse supply pipe 3i.

In operation, when the handle 35 turned to open valve 32 water will flow through the rinse supply line pipe 3|. This flow of Water as it passes through the throat 60 of the Venturi tube 42 produces sufiicient suction through the nipple 65 and the passages formed by the bores 66, I0, II and I3 to cause a charge of disinfectant to flow out of the container I I I, which is under atmospheric pressure, up through tube I I0 and the capillary tube I00 and past the ball 83 which is moved away thereby from the seat I4, and out into the passage 56 at a measured rate of flow where it admixes with the rinse fluid while being carried into the rinse arms 28 of the dish washing machine 20. This action continues at a rela tively uniform rate and provides a flow of disinfectant substantially proportionate to the flow of rinse fluid entering the Venturi tube throughout the entire time of flowof the rinse water and thus the "desired regulated injection of disinfectant is effected, and the flow of disinfectant remains substantially in the originally desired proportion with respect to the flow of rinse fluid so that a properly proportioned disinfectant injection is consistently obtained.

With the rinse supply line fluid pressure maintained constant at about 30* pounds per square inch at the entrance to the Venturi tube 42, and a vacuum produced in the throat 60 of about 12 to 13 inches of mercury, it has been found that with a capillary tube I08 having an inside diameter of the order of .040 inch and about 26 inches in length, connected between the injector mechanism 4] and a supply of disinfectant, there will be metered into about 1.7 gallons of fluid during a ten-second rinse cycle approximately 6.5 cubic centimeters of disinfectant. Under similar conditions of line pressure and Venturi design, it is also possible to secure a uniform injection of the same relatively minute quantity of disinfectant at-a measured rate of flow of the disinfectant into the rinse fluid during a rinse cycle to mix these fluids in approximately the same ratio (about 1 part of a solution per 1000) by using a smaller diameter and shorter length of tube I00.

Itis to be noted also that with' this arrangement and construction of Venturi and the use of a capillary tube of a predetermined and definite diameter and length, there is a substantially proportionate flow of disinfectant with respect to the flow of rinse fluid throughout the entire rinse cycle. .Thus with the pressure in the rinse supply line equal to or greater than that for which the regulatorin the line is set, a substantially constant flow takes place through the Venturi orifice, resulting in the development of substantially uniform vacuum conditions and a uniformly regulated rate of flow of the disinfectant through the capillary tube. Furthermore, if the supply line pressure drops below that for which the regulator is set, there is a reduced volume of flow through the Venturi orifice, but the coordination between the Venturi orifice and the capillary tube is such that the lesser vacuum created results in a lesser flow of disinfectant fluid, and the flow of the latter remains substantially in the originally desired proportion with respect to the flow'of rinse fluid so that a properly proportioned disinfectant injection is consistently obtained.

In the event that it is desired to clean out the capillary tube I00 and the tube I I0, without disconnecting orrernoving these parts, a small portion offluid from the supply line under line pressure can be diverted to flow through these parts ina direction opposite to the normal flow of disinfectant therethrough. This is accomplished by closing valve 32 and rotating the needle valve 90, inthe valve body 43, until the inner end of passage is-open. Fluid from the rinse supply line fills the passage through nipple 65, when valve 32 is closed, and flows around the ball 83 through the enlarged opening 82 and into the lower end of bore 66, then through the inner end of the passage formed by the bore 14 and up through the passage of bore ll into the passage of bore I3 and from there into the capillary tube I00, tube H0 and out through the screen assembly I40 into the container H I. The flow under these conditions is quite limited and does not objectionally dilute the supply of disinfectant, but since full line pressure is available, it serves to maintain the disinfectant line clean and to rupture any film or deposit which may collect over any portion of such line after a period of nonuse.

From the above description it will be apparent that there is provided a compact and automatically operating injector mechanism which utilizes an increase in the velocity of flow of the rinse fluid, with a corresponding reduction in pressure within the same line producing a suction action, to introduce a small quantity at a predetermined rate of flow of fluid disinfectant directly into the rinse fluid supply line so as to insure athorough mixing of the disinfectant and the rinse fluid before the latter is sprayed over the dishes and utensils in the dish washing machine. Such mechanism by utilizing a capillary tube as described provides means for introducing the disinfect-ant into the rinse supply line at a measured rate of flow, thus assuring a constant mixing in the ratio of about one part of a 10% solution per thousand during the entire rinse cycle, and accomplishes this without the use of regulating valves which require frequent attention, in the nature of inspection of operation, adjustment, servicing and repair if a controlled injection and mixing of a small quantity of disinfectant with the rinse fluid is to be secured.

Cross reference is made to applicants co-pending patent applications, Serial No. 672,961 filed May 29, 1946, and Serial No. 692,259 filed August 22, 1946, which are assigned to the same assignee as this application.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

7 What is claimed is:

1. In combination in a washing machine having rinse outlet means, a rinse supply line connected to the rinse outlet means and a separate supply source of disinfectant, a disinfectant injector comprising a Venturi tube connected in said rinse supply line to provide a suction action therein, a valve chamber connected to said rinse supply line and in communication with the throat of said tube, a capillary tube connecting said supply of disinfectant to said chamber and proportioned to conduct a predetermined amount of fluid at a measured rate of flow from said supply of disinfectant into said Venturi tube in response to flow of rinse fluid through said Venturi tube, and a valve positioned in said chamber and adapted to open upon opening of said supply line to connect said capillary tube with said Venturi tube and to close upon closing of said supply line.

2. In combination in a washing machine having rinse outlet means, a rinse supply line connected to the rinse outlet means and a separate supplysource of disinfectant, a disinfectant'injector comprising a Venturi tube connected in said rinse supply line to provide a suction action therein,,a valve chamber connected to said rinse supply line and having a passage in communication with the throat of said Venturi tube. a capillary tube connecting said supply of disinfectant to said passage, a valve positioned in said passage and adapted to open when a supply of rinse fluid is flowing through said Venturi tube to admit a flow of a small quantity of disinfectant fluid at a measured rate of flow from said capillary tube into said passage, said valve closing said passage in the absence of a flow of rinse fluid through said Venturi tube to prevent a flow of rinse fluid through said passage and into said supply of disinfectant, and means for by-passing said valve when closed to provide for delivering a flow of rinse fluid under pressure from said supply line through said capillary tube to clean the same.

- 3. A disinfectant injector adapted for use in a washing machine of the character described having rinse outlet means and a rinse supply line connected to said outlet means, comprising means forming a Venturi having two oppositely diverging passages connected by a Venturi throat, means for directly connecting opposite ends of said venturi in said supply line to form a part thereof, a valve body including a through passage, means for connecting one end of said passage with said Venturi throat, a capillary tube connected at one end with the other end of said passage and adapted at its other end for connection with a supply source of disinfectant to conduct a measured quantity of said disinfectant to said passage for injection into said Venturi throat in response to the flow of rinse fluid through said Venturi, a control valve for said passage positioned in said body adjacent said Venturi throat, said valve having an open position providing for flow of disinfectant through said passage to said throat and a closed position disconnecting said passage from said throat, means for effecting closing of said valve in response to closing of said rinse supply line to maintain said tube and passage substantially filled with disinfectant when said supply line is closed, and said valve being arranged to open in response to the flow of rinse fluid through said Venturi to effect substantially immediate injection of disinfectant into said supply line.

4. A disinfectant injector adapted for use in a washing machine of the character described having rinse outlet means and a rinse supply line connected to said outlet means, comprising means forming a Venturi having two oppositely diverging passages connected by a Venturi throat, means for directly connecting opposite ends of said venturi in said supply line to form a part thereof, a valve body including a through passage, means for connecting one end of said passage with said Venturi throat, a capillary tube connected at one end with the other end of said passage and adapted at its other end for connection with a supply source of disinfectant to conduct a measured quantity of said disinfectant to said passage for injection into said Venturi throat in response to the flow of rinse fluid through said Venturi, a valve positioned in said body to control said passage, means for biasing said valve to closed position tomaintain said tube and passage filled with disinfectant when said rinse supply line is closed, said valve being arranged to open in response to the flow of rinse fluid through said Venturi to effect substantially immediate injection of disinfectant into said supply line, means forming a by-pass passage in said valve body around said valve for supplying rinse fluid under line pressure to said tube to clean the same, and a second valve in said valve body controlling said by-pa-ss passage to prevent flow of rinse fluid to said tube except when said second valve is open.

5. In combination in a washing machine having rinse outlet means, a rinse supply line connected to the rinse outlet means and a separate supply source of disinfectant, a disinfectant 1njector comprising a tube adapted to be inserted in said rinse supply line and including a bore of lesser capacity than said rinse supply line to provide an increase in the velocity of flow of the rinse fluid therethrough with a corresponding reduction in pressure, a valve casing connected with said insert tube, a capillary tube connecting said casing with said disinfectant source, passages in said casing and said insert tube conmeeting said capillary tube with said bore to apply suction to said capillary tubein response to flow of rinse fluid through said supply line and insert tube, said capillary tube being of predetermined diameter and length providing substantially proportionate flow of fluid therethrough for uniform injection of said disinfectant into said rinse fluid during said flow of said rinse fluid, a valve in said casing controlling communication from said capillary tube through said passages, and means normally biasing said valve to closed position to maintain said capillary tube normally filled with disinfectant for substantially immediate injection into said supply line upon the beginning of a rinse cycle, said biasing means being arranged to yield upon application of suction thereto resulting from said flow or rinse fluid to open communication from said capillary tube to said rinse supply line.

GERALD B. FOX. JOHN M. SHERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

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